ADG466 Datasheet, PDF (1/10 Pages) Analog Devices – Triple and Octal Channel Protectors

a
Triple and Octal
Channel Protectors
FEATURES
Fault and Overvoltage Protection up to ؎40 V
Signal Paths Open Circuit with Power Off
Signal Path Resistance of R_ON with Power On
44 V Supply Maximum Ratings
Low On Resistance
ADG466/ADG467 60 ⍀ typ
1 nA Max Path Current Leakage @ +25؇C
Low R_ON Match (5 ⍀ max)
Low Power Dissipation 0.8 ␮W typ
Latch-Up Proof Construction
APPLICATIONS
ATE Equipment
Sensitive Measurement Equipment
Hot-Insertion Rack Systems
ADG466/ADG467
FUNCTIONAL BLOCK DIAGRAMS
V_DD V_SS
V_D1
V_S1
V_D2
V_S2
V_D3
V_S3
ADG466
V_DD V_SS
V_D1
V_S1
V_D2
V_S2
V_D3
V_S3
V_IN
V_IN
V_DD
V_D8
V_S8
V_OUT
ADG467
V_OUT
V_DD
GENERAL DESCRIPTION
The ADG466 and ADG467 are triple and octal channel pro-
tectors, respectively. The channel protector is placed in series
with the signal path. The channel protector will protect sensitive
components from voltage transience in the signal path whether
the power supplies are present or not. Because the channel
protection works whether the supplies are present or not, the
channel protectors are ideal for use in applications where
correct power sequencing can’t always be guaranteed (e.g., hot-
insertion rack systems) to protect analog inputs. This is dis-
cussed further, and some example circuits are given in the
Applications section of this data sheet.
Each channel protector has an independent operation and con-
sists of an n-channel MOSFET, a p-channel MOSFET and an
n-channel MOSFET, connected in series. The channel protec-
tor behaves just like a series resistor during normal operation,
i.e., (V_SS + 2 V) < V_IN < (V_DD – 1.5 V). When a channel’s ana-
log input exceeds the power supplies (including V_DD and V_SS =
0 V), one of the MOSFETs will switch off, clamping the output
to either V_SS + 2 V or V_DD – 1.5 V. Circuitry and signal source
protection is provided in the event of an overvoltage or power
loss. The channel protectors can withstand overvoltage inputs
from –40 V to +40 V. See the Circuit Information section of
this data sheet.
The ADG466 and ADG467 can operate off both bipolar and
unipolar supplies. The channels are normally on when power is
connected and open circuit when power is disconnected. With
power supplies of ± 15 V, the on-resistance of the ADG466 and
OUTPUT CLAMPED
@ V_DD – 1.5V
ADG467 is 60 Ω typ with a leakage current of ± 1 nA max.
When power is disconnected, the input leakage current is ap-
proximately ±5 nA typ.
The ADG466 is available in 8-lead DIP, SOIC and µSOIC
packages. The ADG467 is available in an 18-lead SOIC package
and a 20-lead SSOP package.
PRODUCT HIGHLIGHTS
1. Fault Protection.
The ADG466 and ADG467 can withstand continuous volt-
age inputs from –40 V to +40 V. When a fault occurs due to
the power supplies being turned off or due to an overvoltage
being applied to the ADG466 and ADG467, the output is
clamped. When power is turned off, current is limited to the
microampere level.
2. Low Power Dissipation.
3. Low R_ON.
ADG466/ADG467 60 Ω typ.
4. Trench Isolation Latch-Up Proof Construction.
A dielectric trench separates the p- and n-channel MOSFETs
thereby preventing latch-up.
REV. A
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